Question
Hello Jim,
I planted a 7 ft ponderosa pine six weeks ago and the needles are turning yellow/pale green.  Some are brown.  When I planted the tree the nursery staked it and advised watering thoroughly once a week.
The location of the tree was between my driveway and a neighbors yard.  He waters his grass everyday and his sprinkler happens to hit the area where I planted the pine tree. He waters approximately 15 min each day and it leaves the soil under my pine damp to a depth of approximately 5 inches.  Because of that I was concerned about over-watering so I refrained from watering once per week.  In fact, over the first three weeks I watered it thoroughly only once.  I just watered it thoroughly again yesterday.  Now I am concerned about losing the tree and I'm not sure if the needle discoloration is due to underwatering or overwatering or neither, or what is going on.  I'd sure like to save the tree though.  Any comments would be appreciated.  Thanks.
Brad

Answer
I would say under watering. A tree needs about 1 inch of water per week. 15 minutes of sprinkler for lawns may not be enough to get enough water deep enough for the root to use. The soil needs to be wet down to 12 inches at least. I would place a pan under the tree and turn a sprinkler on and when the pan has 1 inch of water in it stop. Or you can buy a water probe and deep water the tree with this. Most nurseries have water probes. With newly planted tree this time of the year I would water every three days when it does not rain.
Some shock from planting a tree in the form of some needles browning is normal but if the tree does not get enough water the roots start to die and you may see more needles dying.